1. Field of the Invention
The present invention generally relates to a security management method in a mobile communication system and a system thereof, and in particular, to a security management method in a mobile communication system using Mobile Internet Protocol (IP) and a system thereof.
2. Description of the Related Art
Owing to the remarkable progress of the Internet technology, IP-based communication networks have been rapidly developing. In an IP-based communication network, a user terminal can exchange data with a system that provides a service, using an allocated IP address. In addition, there are several methods capable of exchanging data using a network addressing system for transmitting data to a mobile terminal, or mobile node, even in a mobile communication system, and Mobile IP technology is a typical scheme for allocating an IP address to a mobile node, among the methods capable of exchanging data using the network addressing system. The rapid progress of mobile communication system and Wireless Local Area Network (LAN) service technology has caused an increase in numbers of users using mobile nodes. Mobile IP technology manages locations of mobile nodes and provides seamless communication to mobile nodes even during handoff in mobile communication systems.
Mobile IP technology is now under active discussion in an Internet Engineering Task Force (IETF), one of a variety of standard groups, and as to a version of Mobile IP, since Mobile IP v4 (IPv4) was proposed, Mobile IP v6 (IPv6) has recently been proposed. That is, an IP-based communication network based on IPv4 is now evolving into IPv6, an advanced scheme, to increase a limit of allocable IP resources and a number of users and provide various services. A noticeable characteristic of IPv6 lies in an increase in a length of an IP address from 32 bits to 128 bits, enabling accommodation of an increasing number of subscribers.
Mobile IP technology has considerable overhead of the protocol itself when Mobile IP technology is used in a mobile communication system. Therefore, 3rd Generation Partnership Project 2 (3GPP2), a standard group for mobile communication technology, has proposed a Proxy Mobile IP technology to reduce overhead. The Proxy Mobile IP technology is now undergoing standardization. Along with standardization, research is being conducted to use Proxy Mobile IP in mobile communication systems to improve performance. In particular, 3GPP2 intends to use Proxy Mobile IP for performance improvement of handoff, and a corresponding standard is under discussion.
More specifically, a discussion is being made on the overall control and data flow in a mobile communication system using Proxy Mobile IP. However, there is no research on a security mechanism for guaranteeing a safe communication service in a mobile communication system intending to use Proxy Mobile IP. That is, Proxy Mobile IP, compared to existing Mobile IP technology, can reduce latency occurring during handoff, but there is no proposed technology for managing security in a wireless environment supporting Proxy Mobile IP. Therefore, there is a need for a scheme for managing security of mobile nodes in a mobile communication system supporting Proxy Mobile IP.